*4.7. Decolorization*

In order to determine the decolorization efficiency (color removal) of the fermentations, a 0.5 mL sample was mixed well with 14.5 mL distilled water, and the absorbance was measured at 395 nm according to Sayadi and Ellouz [74]. The decolorization percentage was calculated using the equation %A = [(A0− A1)/ A0] × 100, where, A0 is the absorbance at time 0 and A1 is the absorbance at each experimental point during the fermentation.

### *4.8. Determination of Extra-Cellular Nitrogen Into the Fermentation Medium*

Extra-cellular non-assimilated nitrogen was measured in some of the fermentation points of the trials performed according to free amino nitrogen (FAN) determination. FAN concentration into the liquid samples was determined according to Kachrimanidou et al. [72].

### *4.9. Data Analysis*

All experiments and analyses were performed in duplicate. Each experimental point of all of the kinetics presented in the tables and figures is the mean value of two independent determinations. Data were plotted using Microsoft Office Excel Version 2007 showing the mean values with the standard error mean. Throughout the text, indices 0 and max represent the initial and the maximum quantity of the elements in each kinetics presented.
